Conventional pain management is directed toward treating the symptom and not the cause of pain. Conventional methods of treating pain include, as broad categories: (1) oral non-narcotic and/or narcotic medications, (2) physical therapy, (3) chiropractic manipulation, (4) epidural injections or nerve-root blocks, (5) radio-frequency denervation, (6) disc coblation, (7) Intradiscal Electrothermal Annuloplasty and last but not least (8) micro or conventional open spinal surgery. Most of these techniques can be used only for a limited number of times and are not helpful in the long-term management of chronic myofascial pain. The management of chronic pain due to repetitive strain injuries is a $120 billion dollar business in the United States, by 1994 estimates of the U.S. Occupational Safety and Health Administration (OSHA). Low back pain alone is a leading cause for physician visits, second only to the common cold. Neurophysiologically and anatomically based pain management methods that do not use drugs are an effective alternative to conventional care.
It is well established that electrical stimulation may be used to augment needle based pain relief treatments, including acupuncture, IMS therapy, percutaneous electrical nerve stimulation (PENS), transcutaneous electrical nerve stimulation (TENS), and use of interferential current. Surface electrical stimulation termed functional electrical stimulation (FES) is also available for stimulating muscles paralysed due to a stroke or spinal cord injury. Electrical muscle stimulators (EMS devices) and neuromuscular electrical stimulators (NMES) are also readily available commercially.
In electro-acupuncture, stainless steel acupuncture pins serving as electrode pairs are supplied with constant or pulsed direct current. The pins are placed into traditional acupuncture points along traditional imaginary meridians. Electrical stimulus parameters are similar as in percutaneous electrical nerve stimulation (PENS) as described below.
The basic PENS therapy consisted of the placement of ten 32-gauge stainless steel acupuncture-like needle probes into the soft tissue and/or muscle to a 2- to 4-cm depth according to the dermatomal distribution of the pain. The needle probes connect to five bipolar leads (with each lead connected to one positive and one negative probe) from a low-output (<25 mA) electrical generator, which produced a unipolar square-wave pattern of electrical stimulation at a frequency of 4 Hz with a pulse width of 0.5 milliseconds. The intensity of the electrical stimulation is adjusted to produce the maximum tolerable “tapping” sensation without muscle contractions. (reference #2. Ghoname E A. Craig W F. White P F. Ahmed H E. Hamza M A. Henderson B N. Gajraj N M. Huber P J. Gatchel R J. Percutaneous electrical nerve stimulation for low back pain: a randomized crossover study. JAMA. 281(9):818-23, 1999 Mar. 3).
Basic PENS therapy may also consist of the placement of ten 32-gauge (0.2-mm) stainless steel acupuncture-like needle probes (ITO, Tokyo, Japan) into the soft tissue or muscle in the low back region to a depth of 2-4 cm according to the dermatomal distribution of the pain. The needle probes connect to five bipolar leads (with each lead connected to one positive and one negative probe) from a low-output electrical generator, calibrated before each series of treatments. The electrical current is DC, and the duty cycle is continuous. These probes are stimulated at 4/30 Hz for 20 min. The intensity of the electrical stimulation is adjusted to produce the most intense tolerable electrical sensation without muscle contractions. (Yokoyama M. Sun X. Oku S. Taga N. Sato K. Mizobuchi S. Takahashi T. Morita K. Comparison of percutaneous electrical nerve stimulation with transcutaneous electrical nerve stimulation for long-term pain relief in patients with chronic low back pain. Anesthesia & Analgesia. 98(6):1552-6, 2004 June.
Surface applied electrical stimulation known as Interferential therapy (IT) is claimed to work by stimulating muscle fibers. This is presumed to improve the circulation, thus bringing about faster healing of the muscles. IT is stated to speed the healing process by delivering small pulses of electrical current to an injury through electrodes that pass current through the skin and stimulate underlying nerves producing a mild, tingling sensation to provide relief from chronic and acute pain. IF is used for very localized areas where deep current for pain control or increased circulation is needed. Traditional IT uses the principle of mixing a 4 kHz and a 4.001-4.005 kHz frequency to generate the single desired frequency of 1-1000 Hz. The therapeutic frequency moves up and down between 30-60 Hz. to 80-100 Hz [bi-pole; carrier frequency: 4 kHz; pulse duration: 125 microseconds]. (Minder P M. Noble J G. Alves-Guerreiro J. Hill I D. Lowe A S. Walsh D M. Baxter G D. Interferential therapy: lack of effect upon experimentally induced delayed onset muscle soreness. Clinical Physiology & Functional Imaging. 22(5):339-47, 2002 September; Werners R., Pynsent P B., Bulstrode C J: Randomized trial comparing interferential therapy with motorized lumbar traction and massage in the management of low back pain in a primary care setting. Spine. 24(15):1579-84, 1999 Aug. 1.
IT employs a stimulator used for muscle contraction. However as in TENS, with IT stimulation, the muscle will also contract weakly and non-specifically, rather as a muscle pumping motion, in response to the electrical stimulus given at high frequency. These are not the true active muscle contraction via a specific motor end-plate zone activation that cause the muscle to suddenly “jump,” as is sought and obtainable with ATOIMS and ETOIMS (as well as the present inventive SA-ETOIMS technique). This pumping type of contraction continues until the IT unit is turned off after 20 minutes or longer according to the patient's tolerance.
Functional electrical stimulation (FES), also a surface applied method of electrical stimulation therapy, is delivered via the Compex Motion electric stimulator for stimulation of paralysed muscles due to a stroke or spinal cord injuries. The Compex Motion stimulator was designed to serve as a hardware platform for development of diverse FES systems that apply transcutaneous (surface) stimulation technology. It is a microcontroller-based system with four stimulation channels, two input channels A and B, and a special purpose port C. The stimulation channels are current regulated and have 3 μs rise time for pulses with 125 mA amplitudes (pulse amplitude range 0-125 mA, resolution 1 mA; pulse width range 0-16 ms, resolution 500 η-long pulse widths such as 16 ms may be used to stimulate denervated muscles; and stimulation frequency 1-100 Hz, resolution 1 Hz). The input channels A and B can be configured as analog or digital input channels (maximum sampling frequency 8 kHz, voltage range 0-5 V and resolution 20 mV). The special purpose port C is used to interconnect the stimulators, to serially communicate with a PC, and to trigger the stimulator using a push button. By interconnecting stimulators via port C, one can expand the number of stimulation channels from four to multiples of four channels. In such a configuration, one stimulator is designated as a master stimulator while all other stimulators are designated as slaves. The master stimulator paces the stimulation of all connected stimulators and ensures that all stimulators are synchronized and maintain the same “bus frequency” during the entire stimulation protocol. The Compex Motion has a dot matrix LED display that provides a visual interface between the user and the stimulator. (Popovic MR. Keller T. Modular transcutaneous functional electrical stimulation system. Medical Engineering & Physics. 27(1):81-92, 2005 January.)
FES surface electrical stimulation is primarily used for denervated or paralysed muscles because of loss of nerve control as from a stroke or spinal cord injury. The entire muscle contracts when stimulation occurs simultaneously at multiple motor points causing movement of a joint for functional purposes. Muscle groups can be stimulated in overlapping fashion to produce a pumping action. The stimulus frequency is high and is in the range of 1-100 Hz, with very long pulse widths of 16 ms and the stimulation may continue as much as for 6 hours, six days a week. An example would be that of stimulation of the quadriceps, a group of four muscles in the front of the thigh into contraction and to stimulate it long enough hold the contraction in order to keep the knee in extension for use in walking.
Transcutaneous electrical nerve stimulation (TENS) applied onto the skin surface for stimulation of skin nerve fibers is used also in chronic pain management. The stimulus parameters in the high frequency conventional TENS uses frequency 80 Hz, pulse duration 80 μs and patients are instructed to use TENS 4-6 times a day for 1-h periods at sensory threshold intensity. In the high frequency high-intensity TENS group (HIT; frequency 80 Hz, pulse duration 250 μs), patients are instructed to use TENS 4-6 times a day for 30-min periods at maximum tolerated intensity level. In the control TENS group (COT; frequency 30 Hz, pulse duration 250 μs) patients were free to choose stimulus duration and stimulus intensity as they preferred. Two TENS-devices were used: TWIN-STAR (van Lent Systems B.V. Netherlands), TENStem (Schwa Medico Netherlands). Koke A J. Schouten J S. Lamerichs-Geelen M J. Lipsch JS. Waltje E M. van Kleef M. Patijn J. Pain reducing effect of three types of transcutaneous electrical nerve stimulation in patients with chronic pain: a randomized crossover trial. Pain. 108(1-2):36-42, 2004 March.
Standard TENS therapy consisted of the placement of 4 medium-sized (2.5-cm) cutaneous electrode pads in a standardized dermatomal pattern. These electrodes were also stimulated at a frequency of 4/30 Hz for 20 min. (Yokoyama M. Sun X. Oku S. Taga N. Sato K. Mizobuchi S. Takahashi T. Morita K. Comparison of percutaneous electrical nerve stimulation with transcutaneous electrical nerve stimulation for long-term pain relief in patients with chronic low back pain. Anesthesia & Analgesia. 98(6):1552-6, 2004 June).
Usually the stimulation is for excitation of skin receptors only, but frequently the underlying muscle will also contract weakly and non-specifically, rather as a muscle pumping motion, in response to the electrical stimulus over a superficial motor point. These are not the true muscle contractions that cause a sudden muscle “jump” needed to produce a therapeutic effect with twitches as in the present inventor's ATOIMS and ETOIMS techniques (as well as the new SA-ETOIMS technique described herein). The pumping type of contraction produced with the TENS unit continues until the TENS unit is turned off. Usually a TENS treatment lasts 20 minutes or up to a few hours according to the patient's tolerance.
Many electrical muscle stimulators (EMS), such as neuromuscular stimulators (NMS) or high voltage galvanic stimulator (HVGS) using direct or alternating currents, are commercially available. These devices are used to maintain or increase range of motion, re-educate muscles, relax spasms, and increase local blood circulation. Surface applied electrical muscle stimulators units can deliver up to 100 mamp or up to 350 volts to a very low skin impedance load (500-1000 ohms) and are thus capable of producing only non-specific superficial muscle pumping motion continuously or in trains. Additionally, the stimulus frequency in electrical muscle stimulators range from 1-5000 Hz and are designed to contract the muscle through causing a muscle spasm by using very high frequency stimulation briefly and then to allow the muscle to relax. egs. of commercially available electrical muscle stimulators are OMNISTIM® FX2, etc. If twitches are elicited at low frequencies, they are weak and non-specific electrically driven “pump” style contractions in contrast to the sudden “jump” style twitches that are elicited in ATOIMS and ETOIMS (as well as the new SA-ETOIMS technique described herein).
Nerve conduction studies (NCS) are performed by stimulating peripheral nerves through intact skin. These are diagnostic tests and are not used for pain relief. NCS uses stimulus intensities up to 300 volts (this is provided through an electromyographic (EMG) machine that provides constant voltage, maximum 300 volts). The NCS tests can also be performed with constant current stimulation strength up to 100 milliamps through using a different EMG machine that can provide constant current stimulation, with maximum output of 100 milliamp. The stimulus pulse width is 0.05-1 ms at a frequency of 1 Hz. NCS is a diagnostic test and major peripheral nerves are stimulated on the surface of the skin to determine their conductivity to the electrical stimulus. All muscles supplied by the stimulated peripheral nerve will contract and the joint moves forcibly due to contraction of muscles that cross the joint. The stimulus in nerve conduction studies is not isolated to stimulation of individual motor points on a single muscle and adjacent motor end-plate zones, as generally the case with the present inventor's ATOIMS and ETOIMS techniques (as well as the new SA-ETOIMS technique described herein).
Needle techniques used in conjunction with electrical stimulation for pain relief purposes are described below:
PENS and electrical acupuncture use low dose electrical current, and twitches if evoked are generally of relatively very small size since only a tapping motion of the needles is required and may evoke micro-twitches. The duration of the treatment session for electrical stimulation is not standardized and may vary from a few minutes to approximately twenty minutes, depending on the acupuncturist's style and subjective/empirical evaluations. In both PENS and acupuncture, the stimulus is delivered through wiry, stainless steel acupuncture needle insertion and the stimulus strength used is very small. (<25 mA, a unipolar square-wave pattern of electrical stimulation at a frequency of 4 Hz with a pulse width of 0.5 milliseconds). The electrical current is DC, and the duty cycle is continuous. These probes are stimulated at 4/30 Hz for 20 min. The intensity of the electrical stimulation is adjusted to produce the most intense tolerable electrical sensation generally without muscle contractions.
Gunn teaches in his 1996 text, supra, that electrical stimulation can be used in his IMS technique (focused on stimulation of clinical muscle motor points), in place of manual needle agitation, to hasten the release of muscle contracture (pp. 12 and 35-36). Specifically, Gunn teaches (at page 35) that a low-voltage (9-18 V) interrupted direct current may be administered for seconds or minutes to the inserted needle until muscle release is obtained. Gunn further teaches alternatively that the electrical stimulation may be applied for approximately 15-30 minutes, with the current being gradually increased until muscle contractions are visible to confirm that the needles are properly placed. The standard acupuncture pins used in electro-acupuncture and Gunn's IMS technique are conductive along their entire lengths. As a result, the electrical field that is established extends along the length of the inserted portion of the pin, and is dispersed into the skin and subcutaneous tissues, in addition to the target muscle area. The intensity of the electric field actually established at the target area is difficult to accurately calculate and control. Gunn's technique is to apply electrical stimulation for release of the tight muscle fibers in spasm. There is no mention of inducing active muscle contractions to elicit strong muscle twitches through focal muscle contractions as in ETOIMS. Given Gunn's focus on release of spasm within a given muscle, electrical stimulation is stopped once a release of spasm is obtained.
As described in the present inventor's U.S. Pat. No. 6,058,938, non-chemical, needle-applied electrical twitch obtaining intramuscular stimulation (ETOIMS) is used effectively in the management of regional and diffuse myofascial pain (fibromyalgia) of radiculopathic origin where musculoskeletal pain resulting from muscle shortening is the predominant feature. Unlike acupuncture, where many pins that remain stationary are inserted into points on imaginary meridians during a treatment session, in needle-applied ETOIMS generally only one needle (a monopolar electrode) is used at multiple muscle sites during one treatment session. The needle that is inserted into a tender muscle motor point, is used to electrically stimulate the motor end-plate zones to cause the muscle to twitch. The therapeutic effects are best obtained when twitches are forceful enough to either shake or move the joint upon which the muscle acts.
Needle-applied ETOIMS is focused on searching point by stimulated point in a muscle to elicit a strong twitch from active contraction of stimulated muscle fibers through most terminal nerve excitation. Needle-applied ETOIMS uses low frequency stimulus at 1-2 Hz with stimulus applied through a single Teflon coated monopolar needle electrode for 0.5 seconds per stimulated point. This technique is focused on evoking strong twitches. The therapeutic effect of the twitches increases with the force and number of the twitches elicited. Stimulus parameters for electrical intramuscular stimulation are 0.5-1.5 volts, pulse width 0.5 ms and frequency of 2 Hz. Each treatment point is stimulated for 0.5 seconds with fixed amplitude of the alternating current at 2 mA. Needle-applied ETOIMS stimulates the muscle at multiple points in the search for the motor end plate zone that will elicit the strongest force twitch responses at multiple (four or more) points within an afflicted muscle through a localized application of electrical stimulation to multiple motor end plate zones. The technique is applied to have a local focal exercise effect that restores muscle fiber length through a stretch effect. This helps to improve circulation to nerve and muscle in the areas stimulated.
In contrast to conventional pain management, needle-applied electrical twitch obtaining intramuscular stimulation (ETOIMS™), is an effective procedure that can be used repetitively throughout the lifetime of the chronic pain patient, without endangering the health of the patient or causing substantial adverse side effects. Needle-applied ETOIMS™ treats the cause of the muscle pain or muscle discomfort, i.e., muscles shortened or in spasm due to nerve root irritation. When the muscles are shortened due to spasm from nerve root irritation, the muscles pull or tug on adjacent structures to which they attach such as tendons, ligaments, bones, joints, and intervertebral discs. They also compress the intramuscular blood vessels and nerves. This relentless pulling or vice-like effect of the shortened muscles causes more nerve root irritation and more muscle shortening leading to a vicious cycle of acute, sub-acute or chronic nerve related muscle pain. By causing the muscles to twitch with electrical stimulation of the motor point and motor end plate zones, the shortened muscles are stretched and exercised from within the muscle leading to muscle relaxation following the twitch contraction. Muscle relaxation in turn leads to less tugging effect on the pain sensitive tendons, ligaments, bones, joints, intervertebral discs, onto which these muscles attach, and therefore pain reduction or relief of the discomfort is achieved. Successive treatments have a positive accumulative effect from active twitch-induced muscle exercise leading to progressive muscle relaxation. These twitch-induced muscle contractions and immediate relaxation effects allow the intramuscular nerves to heal when blood flow can resume into the relaxed muscle regions as opposed to those intramuscular nerves within taut and tight muscle regions.
Despite the effectiveness in ultimately providing pain relief, needle-applied ETOIMS treatments can be quite painful to the patient who is already in pain. The very nature of the procedure with its need for insertion of a needle, and then electrically stimulating the nerve to cause the muscle to twitch (contract and immediately relax with stretching effects) tends to deflect the needle causing more pain to the patient. The pain is also from the electricity that acts as an irritant to muscles when they are too tight to twitch. Multiple needle insertions are also required repeatedly into many muscles in the search for the motor endplate zones that will yield large force twitches. Oral ingestion of muscle relaxants or anti-anxiety agents, such as Valium (5-10 mgm), and a pain medication, such as 1-2 tablets of Percocet (Oxycodone 5 mg, and Tylenol, 375 mg/tablet) or Morphine Sulfate Immediate Release (MSIR), 15-30 mg, 1 hour before treatment or one unit of Actiq (transmucosal Fentanyl) 200-800 μgms at 15 minutes before treatment can be used to reduce procedural pain.
Even though needle-applied ETOIMS is performed using an automated device that inserts and immediately retracts the needle, the procedure is still laborious, tedious and time-consuming. This may lead to repetitive stress injury to the operator from the need to perform the treatment in a bi-manual fashion. One hand of the operator is used to hold and stabilize the muscle in position while the other hand is used to hold the device for accurate needle penetration into the motor end-plate zone region. The problem for the operator is particularly acute when, as is typically the case, many areas of a patient's body are to be treated in one session, and when the majority of the patients require this type of multi-area intensive treatment. Under these circumstances, the operator performing bi-manual ETOIMS on a long-term basis likely will suffer from repetitive strain injuries.
The present physician inventor has found needle-applied ETOIMS to be very effective in the acute and long-term management of nerve related muscle pain. However, due to use of an automated needling device for therapy, the training in anatomy, peripheral neurology and clinical aspects that has to be given to operators for safe application of treatments is intensive, rigorous, thorough and prolonged. This predictably limits the number of operators who can be trained in needle-applied ETOIMS method.